This invention relates generally to the attachment and adjustment of straps to backpacks or rucksacks, and more particularly pertains to an assembly including a base member adapted to be secured to the backpack and including preferably a pair of parallel track members, a movable member adapted to ride the track members in a slidable attached but nonencircling manner through an adjacent unobstructed volume and to carry the backpack straps, and a locking structure to secure the movable member at selected positions along the track members.